Corrugator

ABSTRACT

A method of making a corrugated medium which permits the use of scrap from a corrugating plant. It includes the steps of forming a web of substantially non-bonded fibres, passing the web through a nip formed by a pair of heated corrugating rolls to corrugate the web and press the fibres into intimate bonding contact thereby to consolidate the web in corrugated form, thereafter applying liners in the conventional manner.

United States Patent [191 Bodycomb CORRUGATOR [75] Inventor: Alistair K. Bodycomb, Baie DUrfe,

Quebec, Canada [73] Assignee: Domtar Limited, Montreal, Canada [22] Filed: July 1, 1971 [21] Appl. No.: 158,851

[52] US. Cl. 156/205, 156/210, 264/285 [51] Int. Cl. B311 1/20, B31f 1/22 I [58] Field of Search... 156/205, 266, 208, 156/207, 210, 209, 470, 471, 473,264/119, 37, 285; 161/59 [56] References Cited UNITED STATES PATENTS 2,689,811 6/1950 Frederick et a1. 264/1 19 2,206,056 10/1935 Sheesley 264/37 [451 Nov. 20, 1973 2,051,025 6/1936 Bauer 156/208 3,536,561 10/1970 Grifi'lths 156/210 3,290,205 12/1966 Goldstein et 156/205 3,671,615 6/1972 Price 264/115 Primary ExaminerAlfred L. Leavitt Assistant Examiner-Frank Frisenda Att0rneyCecil A. Rowley [5 7 ABSTRACT A method of making a corrugated medium which permits the use of scrap from a corrugating plant. It includes the steps of forming a web of substantially nonbonded fibres, passing the web through a nip formed by a pair of heated corrugating rolls to corrugate the web and press the fibres into intimate bonding contact thereby to consolidate the web in corrugated form, thereafter applying liners in the conventional manner.

2 Claims, 2 Drawing Figures Patented Nov. 20, 1973 3,773,588

SINGLE 02 4 Q6 CONSOLIDATOR PACER & s'rmou /00 SCRAP E DRY STORAGE FORMER cousouomou /00 & CORRUGATION FIG. 2

INVENTOR Alistair K. BODYCOMB ATTORNEY CORRUGATOR FIELD OF THE INVENTION The present invention relates to the making of corrugated combined board of the type generally used in the manufacture of boxes or the like. More particularly, the present invention relates to a method of making corrugated medium directly from fibrous material.

DESCRIPTION OF THE PRIOR ART Corrugated board is generally formed by corrugating a medium and then gluing a liner to the tips of the corrugations on each side of the corrugated medium.

In the manufacture of boxes from corrugated board a considerable amount of waste material is formed. This waste material is generally baled and shipped back to a conventional papermaking operation where it is reprocessed to produce further conventional medium or liner, generally bogus medium. This waste material contains a high percentage of Kraft fibres since the liners are generally formed of Kraft and thus provides a very good basic stock material for medium. However, the baling and return of the scrap to the conventional processing plant incurs a considerable amount of extra expense.

It is the object of the present invention to provide a system of making corrugated medium directly from a dry formed non-consolidated web of fibres thereby permitting the direct utilization of waste fibre from the corrugating plant without necessitating the return of baled scrap material to the papermaking operation.

SUMMARY OF THE INVENTION Broadly, the present invention comprises accumulating the corrugator scrap in the board plant, shredding the accumulated scrap into a fibrous mass, laying the fibrous mass as a dry formed mat and forming a corrugated board from the dry formed mat by either pressing to form a medium and subsequently corrugating the medium or, alternatively, substantially simultaneously consolidating the web and forming same into a corrugated medium. Liners may then be applied directly to the corrugated web substantially in the conventional manner.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific web forming machine has not been illustrated as any suitable former may be used. A convenient method and apparatus for forming a web to be corrugated is illustrated in U.S. Pat. No. 3,482,287 issued to Flewwelling. Defiberized corrugated board scrap is a preferred source of fibres, however, it may not always be available and any other suitable fibre or mixture of fibres, natural or synthetic, may be used, e.g., chemical sulphite or semi-chemical pulp fibre which is conventionally used for making corrugated medium.

As shown in FIG. 1, scrap material is collected from various sources as indicated by the arrows and is fed to a central storage or accumulating station 102. From the station 102 the scrap as desired is fed into a shredding station 104 and from the shredder 104 to a suitable dry forming machine 106.

From the dry former the dry formed web, in one embodiment of the invention, is consolidated in the consolidator 108 which in all probability would be a pair of pressure rolls between which the dry formed web is consolidated. Thereafter the consolidated web is corrugated in the conventional manner using a conventional corrugator to form a single-face in the single-facer station designated as 110.

In an alternate system, the dry formed web would be passed into a combined consolidating and corrugating station 112 wherein the dry formed web would be consolidated while simultaneously being shaped into the corrugated configuration as desired. The web leaving this station preferably would be in the form of a singleface with the first liner secured thereto. This arrangement is more clearly described hereinbelow with reference to FIG. 2.

The system of consolidating and corrugating simultaneously will now be described in detail with reference to FIG. 2.

In FIG. 2 a dry formed web 1, wherein the fibres are not permanently bonded, is formed by a suitable dry former schematically illustrated at 50c and is delivered by means of a belt conveyor or the like 2, into the nip between a pair of corrugating rolls schematically illustrated at 11c and 120.

The web will be compacted sufficiently to facilitate feeding to the combined consolidating and corrugating machine.

The corrugating rolls 11c and have longitudinally extending grooves and crests 6 and 7 respectively which form the corrugations in the medium and will be heated by any suitable means (not shown). Suitable means also will be provided for adjusting the pressure in the nip between the rolls. Similarly, means will be provided to drive the rolls 11c and 12c in synchronism to ensure proper pressing of the web under temperature and pressure conditions to consolidate the web into a bonded consolidated board.

As the web passes through the nip of the corrugated rolls 11c and 120 a corrugated medium generally indicated at 8 is formed and this corrugated medium follows around with the roll 12c to a gluing station 9 wherein glue is applied by means of a roll 10c. From the gluing station 9 the corrugated web 8 carries with the roll 120 into a liner applying station wherein a liner 16c is applied to the pre-glued flutes of the medium 8 by means of applicator roll 180. A single-face 20c composed of the liner l6 and corrugated medium 8 then may be delivered to a suitable double-backer (not shown) wherein a second liner may be applied to the exposed flutes of the corrugated medium 8.

In the forming of the corrugated web 8, sufficient pressure must be generated between the two rolls 11c and 120 to ensure that the fibres are brought into intimate contact with one another and the temperature of the rolls is such as to facilitate bonding between the fibres thereby to form a consolidated, bonded, corrugated web.

In operating with a combined consolidator and corrugator care must be taken to ensure that the stresses applied to the web 1 as it enters between the corrugating rolls are not sufficient to break the web, thus the feed of the input conveyor 2 should be properly correlated with that of the rolls 11c and 120. if the corrugating rolls rotate at too high a speed the web 1 may be mangled and care must be taken to ensure that this does not happen, i.e., the maximum tension applied to the web 1 as it is drawn into the rolls 11c and 12c must be less than that which would unduly elongate the web 1 or that would completely separate the web into discrete sections.

In operation, fibres are formed into a mat in the dry former schematically illustrated at 50c, and this dry formed mat l is fed via conveyor 2 between the rolls 11c and 12c. As the mat 1 passes through the nip between the rolls 11c and 120 it is corrugated and consolidated into a permanently bonded corrugated web 8 by the heat and pressure applied to it through the rolls 11c and 120. After the corrugated web 8 leaves the nip between the rolls 11c and 120, adhesive is applied to the tips of the flutes at adhesive applying station 9 and a liner 160 is applied to these tips via application roll 180 to form a single face 200 composed of the corrugated medium 8 and the liner 160. As above indicated, a second liner may be adhesively applied to the tips on the opposite face of the medium 8 thereby to form a combined board in the conventional manner but having a special corrugated medium.

If desired, suitable additives may be incorporated in the dry formed web during or after formation, and the web consolidated thereby to provide a consolidated web having selected characteristics dependent on the characteristics imparted by the additives.

While it is preferred to recycle scrap fibres for production of the corrugated medium, as above indicated new fibres may also be used if desired or fibres from any other suitable source may be substituted for the reconstituted scrap.

Modifications may be made without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. A method of making a combined corrugated paperboard comprising dry forming a web of fibres, said fibres being substantially non-permanently bonded and capable of moving relative to one another within said web when subjected to said stresses incurred during corrugating, pressing said web in a nip formed between a pair of corrugated rolls to corrugate said web and to effect bonding between the fibres thereby to consolidate said web into the form of a corrugated medium and securing a liner to the tips of the corrugations on one side of said corrugated medium.

2. A method as defined in claim 1 further comprising carrying said formed corrugated web on one of said pair of corrugating rolls through an adhesive applying station, applying adhesive to the exposed tips of said formed corrugated medium and wherein said liner is applied to said tips and secured to said web to form a single-face before said web is separated from said one roll.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No: 3,773,588 Dated: November 20, 1973 ALISTAIR K. BODYCOMB It is certified that error appears in the above identified patent and that said Letters Patent is hereby corrected as shown below:

Title Page: Below [21] Appl. No. 158,851

Insert: [30] Foreign Application Priority Date July 8, 1970 Canada 087,713

Signed and sealed this 17th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. A method of making a combined corrugated paperboard comprising dry forming a web of fibres, said fibres being substantially non-permanently bonded and capable of moving relative to one another within said web when subjected to said stresses incurred during corrugating, pressing said web in a nip formed between a pair of corrugated rolls to corrugate said web and to effect bonding between the fibres thereby to consolidate said web into the form of a corrugated medium and securing a liner to the tips of the corrugations on one side of said corrugated medium.
 2. A method as defined in claim 1 further comprising carrying said formed corrugated web on one of said pair of corrugating rolls through an adhesive applying station, applying adhesive to the exposed tips of said formed corrugated medium and wherein said liner is applied to said tips and secured to said web to form a single-face before said web is separated from said one roll. 